What the below passages show is that Paul did not claim to be authorized by Jesus. He claimed to be graced by God to preach of Jesus. This severely opposes what Jesus supposedly told his disciples.
18And Jesus came and said to them, "All authority in heaven and on earth has been given to me. (Matt. 28:18)
The mystery was made known to him by revelation. -Or shall we say, by intuition:
3how the mystery was made known to me by revelation, as I have written briefly. (Eph. 3:3)
His knowledge did not come through other men, but through revelation. -The gospel he refers to was not the written gospel ("gospel" means "good news"):
11For I would have you know, brethren, that the gospel which was preached by me is not man's gospel.
12For I did not receive it from man, nor was I taught it, but it came through a revelation of Jesus Christ. (Gal. 1:11-12)